Answer:
You need to have the Netscape Navigator plug-in that is automatically installed
with the Windows Media Player. The plug-in, Npdsplay.dll, is copied to the
"C:\Program Files\Windows Media Player" folder during setup. If this file is
present, the plug-in will have been installed for all detected NetScape
Navigator installations.

Once the player is installed, you may need to refresh your Web page (which
should contain "navigator.plugins.refresh();") to get the plug-in table updated.
Alternatively, you can enter "navigator.plugins.refresh();" in the address bar,
and then reload the current page.

Note In Netscape Navigator 6.0, you may encounter some problems with
streaming media content. The plug-in architecture in Navigator 6 has been
completely redesigned, which breaks compatibility with existing plug-ins. We are
aware of the issue. No workaround is available at this time. The Windows Media
Plug-in remains compatible with earlier versions of Netscape Navigator and other
browsers.